LONDON: The head of Britain`s domestic spy agency MI5 issued a rare public apology on Wednesday for providing `incorrect information` to London`s High Court over a BBC investigation that said one its agents was a violent right-wing extremist.

The BBC said that during its reporting on the man, referred to as Agent X, the secret service had misled the courts about its longstanding policy of neither confirming nor denying the identities of informants, a policy known as NCND.

The broadcaster said it had been unable to name the man because the government had gained an injunction to block it from doing so using the NCND policy as a justification. But it said a senior MI5 officer had subsequently breached that policy by saying they had been legally authorised to say X was an agent and by confirming the man`s status in a recorded phone call to one of its reporters.

`It has become clear that MI5 provided incorrect information to the High Court in relation to an aspect of our witness statement,` MI5 chief Ken McCallum said in a statement. `We take our duty to provide truthful, accurate and complete information very seriously, and have offered an unreserved apology to the court.

British interior minister Yvette Cooper said she had commissioned an external review to establish the facts of the case and prevent anything similar in future.

`It is clearly a very serious matter to provide incorrect information to the court,` Cooper said in a statement, adding that the government would continue to support the NCND policy.-Reuters